Journal of Environmental Protection, 2010, 1, 41-52
doi:10.4236/jep.2010.11006 Published Online March 2010 (http://www.SciRP.org/journal/jep)
1
Modeling of Climatic Parameters and Determination of Climatic
Differences in the City of Elazig-Turkey and its Close Regions
Sinan Akpinar1, Ebru Kavak Akpinar2*
1Physics Department, Firat University, Elazig, Turkey; 2Department of Mechanical Engineering, Firat University, Elazig, Turkey.
Received December 27th, 2009; revised January 22nd, 2010; accepted January 22nd, 2010.
ABSTRACT
This study deals with the climatic parameters and the climatic differences in Elazig and its close regions (cities of
Malatya, Tunceli, Bingöl, Erzincan). Data on mean monthly temperature, daily maximum-minimum temperature, rela-
tive humidity, pressure, wind speed, rainfall, solar radiation and sunshine duration were analyzed and modeled for
10-year period, from 1994 to 2003. Malatya city was the hottest area whole period, while the Erzincan city was the
coldest area. Maximum temperatures were at highest values in Tunceli. Minimum temperatures reached the warmest
values in the Malatya. Erzincan city was the most hu mid area almo st thro ugh out th e period while Ma latya was the lea st
humid area. Wind speed reached the highest values in the Elazig and the lowest values in the Tunceli. Pressure reached
the highest values in the Malatya and the lowest values in the Erzincan. Direct solar radiation reached the highest val-
ues in the Tunceli and the lowest values in the Erzincan. Sunshine duration reached the highest values in the Malatya
and the lowest values in the Erzincan. A regression analysis was carried out by using the linear regression technique to
model the climatic parameters. The models developed can be used in any study related to climatic and its effect on the
environment and energy. The models developed in this study can be used for future predictions of the climatic parame-
ters and analysing the en vironmental and energy related issues in Elazig and its close reg ions (cities of Malatya, Tun-
celi, Bingöl, Erzincan).
Keywords: Energy, Environment, Elazig, Erzincan, Malatya, Tunceli, Bingöl-Turkey, Relative Humidity, Solar
Radiation, Sunshine Duration, Temperature, Weather Parameters, Wind Speed
1. Introduction
Energy is one of the precious resources in the world. En-
ergy conservation becomes a hot topic around people, not
just for deferring the depletion date of fossil fuel but also
concerning the environmental impact due to energy con-
sumption [1]. Performance of environment-related sys-
tems, such as heating, cooling, ventilating and air-condi-
tioning of buildings (HVAC systems), solar collectors,
solar cells, greenhouses, power plants and cooling towers,
are dependent on weather variables like solar radiation,
dry-bulb temperature, wet-bulb temperature, humidity,
wind speed, etc. In order to calculate the performance of
an existing system or to predict the energy consumption
of a system in design step, the researcher/designer needs
appropriate weather data [2].
A number of studies are found in the literature dealing
with the weather characteristics, solar and wind energy
related issues for different region of the World. Global
solar irradiation (GSI) had been estimated in a number of
studies by the known climatic parameters of bright sun-
shine duration [3,4], cloud fraction [5,6], air temperature
range [7], precipitation status [8], both temperature and
rainfall [9] and both sunshine duration and cloud [10,11],
trends to years of the weather parameters such as tem-
perature, relative humidity, wind speed, dust and fog [12].
Climatic differences between urban and suburban have
been studied by many other authors [13–19].
The main objective of the present study is
1) to investigate the climatic differences between
Elazig city and its close regions, cities of Malatya, Tun-
celi, Bingöl, Erzincan, for 10-year period, from 1994 to
2003.
2) to discuss the climatic parameters (such as tem-
perature, relative humidity, wind speed, pressure, solar
radiation, and sunshine duration) in the Elazig city and
its close regions using the linear regression model.
2. Material and Methods
2.1 Features of Study Area
City of Elazig (longitude; 38º 40’, latitude; 39º 14’, ele-
vation of 991 m), Malatya (longitude; 38º 21’, latitude;
38º 19’, elevation of 898 m), Tunceli (longitude; 39º 07’,

42 Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions
latitude; 39º 33’ elevation of 980 m), Bingöl (longitude;
38º 53’, latitude; 40º 29’, elevation of 1177 m) and Erz-
incan (longitude; 39º 45’, latitude; 39º 30’, elevation of
1218 m) is situated in east Anatolia region of Turkey.
City of Elazig, Malatya, Tunceli, Bingöl and Erzincan
has a typical highland climate, in that it is generally cold
in winter and hot in summer and there are considerable
temperature differences between day and night. Location
of Elazig, Malatya, Tunceli, Bingöl and Erzincan city can
be shown from Figure 1. The mean monthly temperature,
daily maximum–minimum temperature, relative humidity,
pressure, wind speed, solar radiation and sunshine dura-
tion were the measured meteorological parameters of this
research. The measurements have been carried out by
conventional meteorological instruments by the Turkish
Meteorological State Department (TMSD).
2.2 Modelling of Climatic Parameters
Statistical techniques of regression models are frequently
used to study a set of experimental data. Adequacy and
validity of the model is performed to determine if the
model will function in a successful manner in its in-
tended operating field.
Linear regression analysis is a statistical tool by which
a line is fitted through a set of experimental data using
the least-squares method. Regression is used in a wide
variety of applications in order to analyze how a single
dependent variable is affected by the values of one or
more independent variables. In this study, temperature,
relative humidity, wind speed, pressure, solar radiation
and sunshine duration collected for a period of 10 years
(1994–2003) is modelled using linear regression analysis
with 95% confidence level.
For the purpose of checking the adequacy of the mod-
els developed in this study, residual analysis was adopted.
It is important to examine plots of residuals versus the
corresponding predicted values of weather parameters to
detect common patterns such as horizontal bands, out-
ward openings, double bows, and curved bands [12]. The
Figure 1. Location of city of Elazig, Erzincan, Tunceli,
Malatya and Bingöl in Turkey
desirable pattern for a good model is one in which the
residuals are contained within a horizontal band. Model
validation is also essential for model building, since a
model that fits the data well may not work well for pre-
dictions.
3. Results
From the data obtained over a 10-year period between
1994 and 2003, the results of study were summarized at
Table 1, results are as following:
3.1 The Differences in the Mean Monthly
Temperatures
From Figure 2, it can be seen that there was an evident
difference at mean monthly temperatures between the
investigated cities. Mean monthly temperatures was
showed changing between 0.6 and 27.5°C for Elazig city,
–0.9 and 24.7°C for Erzincan city, 0.3 and 27.8°C for
Tunceli city, 1.6 and 27.9°C for Malatya city, –0.7 and
27.1°C for Bingöl city. The overall average temperature
for 10 years was found to be about 13.19°C for Elazig,
11.50°C for Erzincan, 13.75°C for Tunceli, 14.14°C for
Malatya, 12.56°C for Bingöl. While the Erzincan city
was the coldest area whole period, Malatya city was the
hottest area whole period. However, Malatya was
warmer than Tunceli, Elazig and Bingöl in terms of av-
erages, respectively. Mean monthly temperatures of city
of Elazig, Tunceli and Bingöl were showed changing at
the close values to each other for month of April, May,
June, July, August, September, October, November. The
highest difference in mean temperature between Elazig
and Malatya, Elazig and Tunceli, Elazig and Bingol,
Elazig and Erzincan was 1.5°C at September, –0.6°C at
December, –1.6 °C at February and –2.8°C at July, re-
spectively. The lowest difference in mean temperature
between Elazig and Malatya, Elazig and Tunceli, Elazig
and Bingol, Elazig and Erzincan was 0.3°C at December,
0.1°C at March and April, –0.1°C at August, September,
November, May, June and –0.6°C at April, respectively.
There was a mean temperature difference of 0.96, 0.083,
–0.63 and –1.56°C between Elazig and Malatya, Elazig
and Tunceli, Elazig and Bingol, Elazig and Erzincan,
respectively (Table 1). These data can be seen that mean
monthly temperatures of Elazig was about equal to mean
monthly temperatures of Tunceli.
3.2 The Differences in Maximum Temperatures
From Figure 3, maximum temperatures were at highest
values in Tunceli, followed by Malatya, Elazig, Bingöl
and Erzincan. Mean maximum monthly temperatures
was showed changing between 4.3 and 34.8°C for Elazig
city, 3.9 and 32.4 °C for Erzincan city, 4.8 and 35.3°C
for Tunceli city, 5.2 and 34.4°C for Malatya city, 3.7 and
35.1°C for Bingöl city. While maximum temperatures

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 43
Table 1. Differences in the climatic elements between cities
Parameters Elazig-Malatya Elazig-Tunceli Elazig-Bingöl Elazig-Erzincan
Mean temperature (°C) 0.96 0.083 –0.63 –1.56
Maximum temperature (°C) 0.26 0.34 –0.40 –1.30
Minimum temperature (°C) 1.60 0.16 0.066 –1.35
Relative humidity (%) –5 –0.083 –1.083 5.91
Wind speed (m/s) –0.9 –1.55 –1.40 –1.19
Pressure (mbar) 4.41 1.1 –16.2 –24.61
Direct solar radiation (cal/cm2) 19.29 24.17 9.93 –6.30
Sunshine duration (min) 12.08 –22.58 –72.58 –92.25
-5
0
5
10
15
20
25
30
August
Sept e mber
October
November
December
January
February
March
April
May Ju ne
Ju l y
Months
Temperature (
o
C)
Elazig Erzincan Tunceli Malatya Bingöl
Figure 2. Monthly mean temperatures during the years 1994–2003 for the cities
0
5
10
15
20
25
30
35
40
August
Sept em ber
October
November
December
January
Fe bruary
March
April
May June
July
Months
Temperature (
o
C)
Elazig Erzincan Tunceli Malatya Bingöl
Figure 3. Monthly mean maximum temperatures during the years 1994–2003 for the cities

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 44
were at highest values in August and July, at lowest val-
ues in January. The highest difference in maximum mean
temperature between Elazig and Malatya, Elazig and
Tunceli, Elazig and Bingol, Elazig and Erzincan was
0.9°C at January, 0.9°C at August and November, –1.7°C
at March and –2.5°C at July, respectively. The lowest
difference in maximum temperature between Elazig and
Malatya, Elazig and Tunceli, Elazig and Bingol, Elazig
and Erzincan was 0°C at June, 0°C at April, –0.1°C at
October and May and –0.4°C at January, respectively.
There was a mean maximum temperature difference of
0.26, 0.34, –0.40 and –1.30°C between Elazig and
Malatya, Elazig and Tunceli, Elazig and Bingol, Elazig
and Erzincan, respectively (Table 1). While Erzincan
was coldest city whole period, Tunceli was warmest city.
Malatya was warmer than cities of Elazig and Bingöl.
Values of maximum temperature of Elazig were close to
values of maximum temperature of Malatya and Tunceli.
3.3 The Differences in Minimum Temperatures
Mean minimum monthly temperatures was showed
changing between –3 and 18.7°C for Elazig city, –4.8 and
16.6°C for Erzincan city, –3.5 and 19.5°C for Tunceli
city, –1.5 and 20.3°C for Malatya city, –4.2 and 19.7°C
for Bingöl city (Figure 4). While minimum temperatures
were at highest values in July, at lowest values in January
and February. The highest difference in minimum mean
temperature between Elazig and Malatya, Elazig and
Tunceli, Elazig and Bingol, Elazig and Erzincan was
2.3°C at September and May, 0.8°C at June, July and
January, –1.4°C at December and June and –2.1°C at De-
cember, January and July, respectively. The lowest dif-
ference in minimum mean temperature between Elazig
and Malatya, Elazig and Tunceli, Elazig and Bingol,
Elazig and Erzincan was 0.4°C at December, 0.2°C at
October, 0.1°C at November and –0.3°C at April and
May, respectively. There was a mean minimum tem-
perature difference of 1.60, 0.16, 0.066 and –1.35°C be-
tween Elazig and Malatya, Elazig and Tunceli, Elazig
and Bingol, Elazig and Erzincan, respectively (Table 1).
Minimum temperatures reached the warmest values in
the Malatya. Malatya was followed by Tunceli, Bingöl,
Elazig and Erzincan. Minimum temperatures were at
lowest values in Erzincan. However, values of mean
minimum temperature of Elazig were almost equal to
values of mean minimum temperature of Bingöl and
Tunceli.
3.4 The Differences in Relative Humidity
Erzincan city was the most humid area almost throughout
the period while Malatya was the least humid area.
However, values of mean relative humidity of Elazig
were almost equal to values of mean relative humidity of
Tunceli. Bingöl was less humid than Elazig and Tunceli.
Mean monthly relative humidity was showed changing
between 36 and 74% for Elazig city, 51 and 76% for
Erzincan city, 37 and 74% for Tunceli city, 31 and 74%
for Malatya city, 37 and 74% for Bingöl city (Figure 5).
The overall average humidity ratio was found to be about
57.69% for Elazig, 63.52% for Erzincan, 57.40% for
Tunceli, 52.76% for Malatya 56.59% for Bingol. While
relative humidity was at highest values in December and
-10
-5
0
5
10
15
20
25
Augus t
September
October
Novembe r
Decembe r
January
February
March
April
May June
July
Months
Temperature (
o
C)
Elazig Erzincan Tunceli Malatya Bingöl
Figure 4. Monthly mean minimum temperatures during the years 1994–2003 for the cities

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 45
0
10
20
30
40
50
60
70
80
August
September
October
November
December
January
February
March
April
May June
July
Months
Relative humidity (%
Elazig Erzincan Tunceli Malatya Bingöl
(%)
Figure 5. Monthly mean relative humidity values during the years 1994–2003 for the cities
0
0.5
1
1.5
2
2.5
3
3.5
August
September
October
November
December
January
February
March
April
May June
July
Months
Wind speed (m/s)
Elazig Erzincan Tunceli Malatya Bingöl
Figure 6. Monthly mean wind speed values during the years 1994–2003 for the cities
January, at lowest values in July and August. The highest
difference in mean relative humidity between Elazig and
Malatya, Elazig and Tunceli, Elazig and Bingol, Elazig
and Erzincan was –7% at March, April and May, 3% at
October and May, 4% at November and January and 15
% at July, respectively. The lowest difference in mean
relative humidity between Elazig and Malatya, Elazig
and Tunceli, Elazig and Bingol, Elazig and Erzincan was
0% at December, 0% at December, 0% at December and
June and 0% at January and March, respectively.
There was a mean relative humidity difference of –5%,
–0.083%, –1.083% and 5.91% between Elazig and
Malatya, Elazig and Tunceli, Elazig and Bingol, Elazig
and Erzincan, respectively (Table 1).
3.5 Differences in Wind Speed
While the windiest city was Elazig, it was followed by
Malatya, Erzincan, Bingöl and Tunceli (Figure 6). Mean
monthly wind speed was showed changing between 2.5
and 3.1 m/s for Elazig city, 1.1 and 1.9 m/s for Erzincan
city, 0.8 and 1.5 m/s for Tunceli city, 1.3 and 2.2 m/s for
Malatya city, 0.9 and 1.8 m/s for Bingöl city (Figure 6).

46 Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions
The overall average of wind speed for the same period
was obtained to be approximately 2.69 m/s for Elazig,
1.47 m/s for Erzincan, 1.21 m/s for Tunceli, 1.79 m/s for
Malatya, 1.3 m/s for Bingol. The highest difference in
the mean wind speed between Elazig and Malatya, Elazig
and Tunceli, Elazig and Bingol, Elazig and Erzincan was
–1.2 m/s at November, December and January, –1.8 m/s
at November, –1.8 m/s at February and March and –1.4
m/s at October, November, January, February and March,
respectively. The lowest difference in mean wind speed
between Elazig and Malatya, Elazig and Tunceli, Elazig
and Bingol, Elazig and Erzincan was –0.6 m/s at August
and July, –1.3 m/s at December, –0.9 m/s at July and –0.8
m/s at July, respectively. There was a mean wind speed
difference of –0.9 m/s, –1.55 m/s, –1.40 m/s and –1.19 m/s
between Elazig and Malatya, Elazig and Tunceli, Elazig
and Bingol, Elazig and Erzincan, respectively (Table 1).
3.6 The Differences in Mean Pressure
Mean monthly pressure was showed changing between
896.7 and 907.3 mbar for Elazig city, 874.2 and 881.6
mbar for Erzincan city, 898.3 and 908.1 mbar for Tunceli
city, 901.5 and 911.6 mbar for Malatya city, 881 and
890.7 mbar for Bingöl city (Figure 7). The overall pres-
sure was found to be about 902.74 mbar for Elazig,
878.03 mbar for Erzincan, 903.79 mbar for Tunceli,
907.19 mbar for Malatya, 886.50 mbar for Bingol. While
pressure values were at highest values in November and
December, at lowest values in July. The highest differ-
ence in mean pressure between Elazig and Malatya,
Elazig and Tunceli, Elazig and Bingol, Elazig and Erz-
incan was 4.9 mbar at June, 1.8 mbar at May, –16.9 mbar
at January and –26.1 mbar at December, respectively.
The lowest difference in mean pressure between Elazig
and Malatya, Elazig and Tunceli, Elazig and Bingol,
Elazig and Erzincan was 4 mbar at October, 0.3 mbar at
October, –15.5 mbar at June and –22.5 mbar at July, re-
spectively. There was a mean pressure difference of 4.41,
1.1, –16.2 and –24.61 mbar between Elazig and Malatya,
Elazig and Tunceli, Elazig and Bingol, Elazig and Erz-
incan, respectively (Table 1). Pressure reached the high-
est values in the Malatya. Malatya was followed by
Tunceli, Elazig, Bingöl, and Erzincan. Pressure values
were at lowest values in Erzincan. However, values of
mean pressure of Elazig were close to values of mean
pressure of Tunceli.
3.7 The Differences in Mean Direct Solar Radiation
Mean monthly direct solar radiation was showed chang-
ing between 125.58 cal/cm2 and 592.18 cal/cm2 for
Elazig city, 145.06 and 554.45 cal/cm2 for Erzincan city,
139.78 and 628.3 cal/cm2 for Tunceli city, 138.28 and
599.1 cal/cm2 for Malatya city, 132.73 and 621.44
cal/cm2 for Bingöl city (Figure 8). The overall average
of solar radiation for the same period was obtained to be
approximately 363.06 cal/cm2 for Elazig, 356.69 cal/cm2
for Erzincan, 385.6 cal/cm2 for Tunceli, 382.38 cal/cm2
for Malatya, 373.15 cal/cm2 for Bingol. While direct so-
lar radiation values were at highest values in June and
July, at lowest values in December. The highest differ-
ence in direct solar radiation between Elazig and Malatya,
Elazig and Tunceli, Elazig and Bingol, Elazig and Erzin-
can was 36.5 cal/cm2 at August, 45.23 cal/cm2 at August,
850
860
870
880
890
900
910
920
Au gust
Se pt e mbe r
October
November
December
January
February
March
Apri l
May June
July
Month
Pressure (mbar)
Elazig ErzincanTunceli Malatya Bingöl
Figure 7. Monthly mean pressure values during the years 1994–2003 for the cities

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 47
0
100
200
300
400
500
600
700
August
September
October
November
December
January
Fe b r uar y
March
April
May Ju n e
July
Months
Direct solar radiation (cal/cm
2
)
Elazig Erzincan Tunceli Malatya Bingöl
Figure 8. Monthly mean solar radiation values during the years 1994–2003 for the cities
0
100
200
300
400
500
600
700
800
August
September
October
November
December
January
Fe bruary
March
April
May Ju ne
Ju ly
Month
Sunshine duration (min
)
Elazig Erzincan Tunceli Malatya Bingöl
Figure 9. Monthly mean sunshine duration values during the years 1994–2003 for the cities
34.29 cal/cm2 at August and –45.24 cal/cm2 at July, re-
spectively. The lowest difference in mean direct solar
radiation between Elazig and Malatya, Elazig and Tun-
celi, Elazig and Bingol, Elazig and Erzincan was 6.06
cal/cm2 at June, 8.75 cal/cm2 at April, 1.21 cal/cm2 at
March and –4.66 cal/cm2 at November, respectively.
There was a mean solar radiation difference of 19.29,
24.17, 9.93 and –6.30 cal/cm2 between Elazig and
Malatya, Elazig and Tunceli, Elazig and Bingol, Elazig
and Erzincan, respectively (Table 1). Direct solar radia-
tion reached the highest values in the Tunceli. Tunceli
was followed by Malatya, Bingöl, Elazig and Erzincan.
Direct solar radiation values were at lowest values in
Erzincan. However, values of mean direct solar radiation
of Elazig were very close to values of mean direct solar
radiation of Erzincan.
3.8 The Differences in Mean Sunshine Duration
Mean monthly sunshine duration was showed changing
between 142 and 757 min for Elazig city, 161 and 565
min for Erzincan city, 125 and 718 min for Tunceli city,
201 and 732 min for Malatya city, 124 and 607 min for

48 Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions
Bingöl city (Figure 9). The overall average sunshine
duration for 10 years was found to be about 464.76 min
for Elazig, 369.48 min for Erzincan, 445.74 min for
Tunceli, 476.4 min for Malatya, 396 min for Bingol.
While sunshine duration values were at highest values in
August and July, at lowest values in December. The
highest difference in sunshine duration between Elazig
and Malatya, Elazig and Tunceli, Elazig and Bingol,
Elazig and Erzincan was 59 min at December, –47 min at
May, –154 min at July and –195 min at June, respectively.
The lowest difference in mean sunshine duration between
Elazig and Malatya, Elazig and Tunceli, Elazig and Bin-
gol, Elazig and Erzincan was –1 min at September, 1 min
at November, 9 min at February and –4 min at January,
respectively. There was a mean sunshine duration dif-
ference of 12.08, –22.58, –72.58 and –92.25 min between
Elazig and Malatya, Elazig and Tunceli, Elazig and Bin-
gol, Elazig and Erzincan, respectively (Table 1). Sun-
shine duration reached the highest values in the Malatya.
Malatya was followed by Elazig, Tunceli, Bingöl and
Erzincan. Sunshine duration values were at lowest values
in Erzincan. However, values of mean sunshine duration
of Elazig were very close to values of mean sunshine
duration of Malatya.
4. Regression Analysis of Climatic Parameters
Figures 10–14 show the linear regression results for the
temperature, relative humidity, wind speed, pressure,
solar radiation and sunshine duration respectively, for the
period of 10 years. The linear regression correlations for
these data were obtained for forecasting purposes (Table 2).
Elazig
0
100
200
300
400
500
600
700
800
900
1000
1994 19951996 19971998 19992000 20012002 2003
Years
Pressure (mbar), Relative humidity (%)
Solar radiation (cal/cm
2
), Sunshine
duration (min)
0
2
4
6
8
10
12
14
16
Wind speed (m/s), Temperature (
o
C)
Pressure Relative humidity Solar radiation
Sunshine duration Wind speed Temperature
Figure 10. Linear regression and variations of annual average climatic conditions in Elazig city during the years 1994–2003
Erzincan
0
100
200
300
400
500
600
700
800
900
1000
1994 19951996 19971998 19992000 20012002 2003
Years
Pressure (mbar), Relative humidity (%)
Solar radiation (cal/cm
2
), Sunshine
duration (min)
0
2
4
6
8
10
12
14
Wind speed (m/s), Temperature (
o
C)
Pressure Relative humidity Solar radiation
Sunshine duration Wind speed Temperature
Figure 11. Linear regression and variations of annual average climatic conditions in Erzincan city during the years 1994–2003

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 49
Table 2. Linear regression correlations
Parameters Correlations
Elazig
Temperature, (°C) = –0.0272*Y + 13.347
Relative humidity, (%) = –0.1864*Y + 58.72
Wind speed, (m /s) = –0.0351*Y + 2.892
Pressure, (mbar) = 0.0424*Y x + 902.51
Solar radi ation, (cal/cm2) = 0.9449*Y + 357.87
Sunshine duration, (min) = 1.2436*Y + 457.92
Erzincan
Temperature, (°C) = –0.0866*Y + 11.984
Relative humidity, (%) = 0.5283*Y + 60.618
Wind speed, (m /s) = 0.0057*Y + 1.44
Pressure, (mbar) = 0.0589*Y + 877.71
Solar radi ation, (cal/cm2) = 6.2399*Y + 322.38
Sunshine duration, (min) = 7.0618*Y + 330.64
Tunceli
Temperature, (°C) = 0.2259*Y + 12.509
Relative humidity, (%) = –0.2733*Y + 58.904
Wind speed, (m /s) = –0.0013*Y + 1.22
Pressure, (mbar) = 0.0112*Y + 903.73
Solar radi ation, (cal/cm2) = 2.0678*Y + 374.23
Sunshine duration, (min) = 1.6182*Y + 436.84
Malatya
Temperature, (°C) = 0.0084*Y + 14.097
Relative humidity, (%) = –0.045*Y + 53.013
Wind speed, (m /s) = –0.0373*Y + 2.0028
Pressure, (mbar) = –0.0045*Y + 907.22
Solar radi ation, (cal/cm2) = –0.045*Y + 53.013
Sunshine duration, (min) = –2.6909*Y + 491.2
Bingöl
Temperature, (°C) = 0.0485*Y + 12.293
Relative humidity, (%) = 0.4321*Y + 54.213
Wind speed, (m /s) = –0.0411*Y + 1.526
Pressure, (mbar) = 0.2158*Y + 885.32
Solar radi ation, (cal/cm2) = 3.6787*Y + 352.92
Sunshine duration, (min) = 1.9636*Y + 385.2
Tunceli
0
100
200
300
400
500
600
700
800
900
1000
1994 19951996 19971998 19992000 20012002 2003
Ye a rs
Pressure (mbar), Relative humidity (%)
Solar radiation (cal/cm
2
), Sunshine
duration (min)
0
2
4
6
8
10
12
14
16
18
20
Wind speed (m/s), Temperature (
o
C)
Pressure Relative humidity Solar radiation
Sunshine duration Wind speed Temperature
Figure 12. Linear regression and variations of annual average climatic conditions in Tunceli city during the years 1994–2003
Linear regression models indicate that the pressure re-
mains almost invariant throughout the years considered
for all cities. The temperature showed a slight decrease
with a negative slope for Elazig and Erzincan, a slight
increase with a positive slope for Malatya, Tunceli and
Bingöl. The relative humidity showed a slight decrease
with a negative slope for Elazig, Tunceli and Malatya, a
slight increase with a positive slope for Erzincan and

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 50
Malatya
0
100
200
300
400
500
600
700
800
900
1000
19941995 19961997 19981999 20002001 20022003
Years
Pressure (mbar), Relative humidity (%)
Solar radiation (cal/cm
2
), Sunshine
duration (min)
0
2
4
6
8
10
12
14
16
Wind speed (m/s), Temperature (
o
C)
Pressure Relative humidity Solar radiation
Sunshine duration Wind speed Temperature
Figure 13. Linear regression and variations of annual average climatic conditions in Malatya city during the years 1994–2003
Bingöl
0
100
200
300
400
500
600
700
800
900
1000
19941995 19961997 19981999 20002001 20022003
Years
Pressure (mbar), Relative humidity (%)
Solar radiation (cal/cm
2
), Sunshine
duration (min)
0
2
4
6
8
10
12
14
16
Wind speed (m/s), Temperature (
o
C)
Pressure Relative humidity Solar radiation
Sunshine duration Wind speed Temperature
Figure 14. Linear regression and variations of annual average climatic conditions in Bingöl city during the years 1994–2003
Bingöl. The wind speed slightly decreased with a nega-
tive slope for Elazig, Tunceli Malatya and Bingöl, and
increased with a positive slope for Erzincan. The solar
radiation and sunshine duration increased with a positive
slope for Elazig, Erzincan, Tunceli and Bingöl, and de-
creased with a negative slope for Malatya.
Analysis of the residuals is frequently helpful in
checking the assumption that the errors were approxi-
mately normally distributed with constant variance, as
well as in determining whether linear regression model
would be adequate. Figure 15 shows the residual plots
for the temperature, relative humidity, wind speed, pres-
sure, solar radiation and sunshine duration. As was ob-
vious from this figure there were no serious model in-
adequacies. A general overview of the weather charac-
teristics for the past 10 years indicated that some of the
essential characteristics of weather such as temperature,
relative humidity, wind speed, pressure, solar radiation
and sunshine duration can be modelled and, thus, future
forecasting of such characteristics are possible.
5. Conclusions
In the study, firstly, it was attempted to determine how
much the climatic elements between Elazig and its close
regions (cities of Malatya, Tunceli, Bingöl, Erzincan)
may differ and obtain concrete values. Secondly, linear
regression models was investigated to present climatic
data collected in Elazig and its close regions for a period
of 10 years. These data can be seen that
1) Values of mean monthly temperature, relative humidity

Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions 51
Figure 15. Standard residual plots of temperature, relative humidity, wind speed, pressure, solar radiation and sunshine du-
ration for the investigated cities
and pressure of Elazig were about equal to values of Tunceli.
2) Values of maximum temperature of Elazig were
close to values of maximum temperature of Malatya and
Tunceli.
3) Values of mean minimum temperature of Elazig
were almost equal to values of mean minimum tempera-
ture of Bingöl and Tunceli.
4) Values of mean solar radiation of Elazig were very
(a) Elazig
-40
-30
-20
-10
0
10
20
30
1993 19941995 1996 1997 19981999 2000 20012002 2003
Standart residuals
Pressure (mbar)Relative humidity (%)Solar radiation (cal/cm2)
Wind speed (m/s)Temperaure (oC)Sunshine duration (min)
(b) Erzincan
-40
-30
-20
-10
0
10
20
30
1993 19941995 19961997 1998 19992000 20012002 2003
Standart residuals
(c) Tunceli
-50
-40
-30
-20
-10
0
10
20
30
1993 19941995 19961997 1998 19992000 20012002 2003
Standart residuals
(d) M a latya
-30
-20
-10
0
10
20
30
1993 19941995 19961997 1998 19992000 20012002 2003
Standart residuals
(d) Bingöl
-40
-20
0
20
40
60
1993 19941995 19961997 1998 19992000 20012002 2003
Years
Standart residuals
℃
c
m
2

52 Modeling of Climatic Parameters and Determination of Climatic Differences in the City of Elazig-Turkey and its Close Regions
close to values of mean solar radiation of Erzincan.
5) Values of mean sunshine duration of Elazig were
very close to values of mean sunshine duration of Malatya.
6) Malatya city was the hottest area whole period,
while the Erzincan city was the coldest area. Maximum
temperatures were at highest values in Tunceli.
Minimum temperatures reached the warmest values in
the Malatya. Erzincan city was the most humid area
almost throughout the period while Malatya was the least
humid area. Wind speed reached the highest values in the
Elazig and the lowest values in the Tunceli. Pressure
reached the highest values in the Malatya and the lowest
values in the Erzincan. Direct solar radiation reached the
highest values in the Tunceli and the lowest values in the
Erzincan. Sunshine duration reached the highest values
in the Malatya and the lowest values in the Erzincan. The
factors thought to be effective on the climatic differences
mentioned above may result from the features of the
investigated cities. The factors thought to be effective on
the differences determined in the present study are
briefly canopy and evapo-transpiration effects, elevation
difference between the areas and surface roughness,
radiation and reflection factors, smoke and dust, the
duration and color of snow cover on the ground, wind
direction and other anthropogenic effects of the invest-
tigated city. Depending on the location of the city center,
prevalent easterly and northerly winds in this area is
effective on temperatures and humidity, which can de-
crease temperatures and increase humidity. As is known,
there is a true relationship between the population and
temperature in a city center. This effect may be smaller
compared to those aforementioned, because of the rela-
tively low population and the city lacks of any industrial
facilities that may influence the temperature in the city.
7) The models were reviewed for the statistical ade-
quacy, i.e. the normality assumption is satisfied and the
residual versus the predicted and regressed variables are
contained within a horizontal band. There was little va-
riation between the observed and predicted values of
climatic data, i.e. temperature, relative humidity, wind
speed pressure, solar radiation and sunshine duration. The
models developed in this study can be used for future pre-
dictions of the climatic parameters and analysing the en-
vironmental and energy related issues in Elazig and its
close regions (cities of Malatya, Tunceli, Bingöl, Erzincan).
Nomenclature
Y the year according to the Gregorian calendar
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